Method oe increasing the efeective length oe and cleansing boiler-elites



^ sin sfrarns PATENT orrion.

ABNER CHAPMAN, OF FAIRFAX, VERMONT.

METHOD OF INCREASING THE EFFECTIVE LENGTH OF AND CLEANSING BOILER-FLUES.

Specification of Letters Patent No. 6,595, dated July 1'?, 1849.

To all wiz-0m t may concern Be it kno-wn that I, ABNER CHAPMAN, ofFairfax, in the county of Franklin and State of Vermont, have inventedcertain new and useful Improvements in Flues to Steam- Bo-ilers, andthat the following is a full, clear, and exact description of theprinciple or character which distinguishes it from all other thingsbefore known and of the -usual manner of making, modifying, and usingthe same, reference being had to the accompanying drawing, which is avertical section of the iues.

The nature of my invention consists in furnishing the horizontal fluesof a steam boiler with spiral partitions, which partitions can be madeto revolve to clear the flue, by which arrangement I am enabled toobtain all the advantages of a spiral flue which has been hereto-foreessayed and found useful until it became choked with ashes, &c., when itwas found impossible to clean it, but by my construction the inside 0rspiral iue can be revolved, and thus be made to clean the flueperfectly, while it retains all the advantages of the stationary spiralflue.

The boiler, in which this apparatus is placed can be made of any of theordinary forms, one of which is in part shown in the sectional drawingherewith accompanying, (an) being the boiler, (b, 6,) the iues; in

one of which my apparatus is lixed. This apparatus consists of a shaft(0,) running through the center of the flue, and having its bearings ateach end, so that it can be made to revolve by means of a crank key (6L)that is inserted thro-ugh the man holes; around this shaft a flat thread(6,) of plate metal7 is affixed, that extends from the shaft to thewalls of the flue, as clearly shown in the drawing, forming a spiral iuefrom one end to the other, by which the heat is more perfectly retainedand fuel is thus economized; and it serves also the double purpose of abrace to prevent the flue (6,) from collapsing, and as a scraper to keepit clean.

Having thus fully described my improvement, I wish it t-o be understoodthat I do not claim forming a spiral flue within a steam boiler, as thathas already been done, but

What I do claim as my invention and for which I desire to secure LettersPatent, isf- Spiral partitions, forming a spiral iue within the flues ofa steam boiler, substantially as described, said thread being affixed toa shaft independent of the flue so that it can be made to revolve toscrape the flue, and clean it when it gets foul.

ABNER CHAPMAN. Witnesses:

J. J. GREENOUGH, 1WM. GREENoUGI-I.

